Cannot run dell diagnostics after system restore

I recently had the hard drive fail on an (old but serviceable) Inspiron530 (HDD healthy but corrupt partition table) and restored via dd using recent partition images. After reinstalling grub, all back up and running except that selecting Dell Diagnostics at the grub menu gives a blank screen with flashing cursor.  The only way to get out of this appears to be power off.

Can anyone give me a clue as to how to get the Dell Diagnostics to boot/run?  I suspect there may be a changed UUID somewhere but so far unable to make any progress.

Any assistance would be gratefully received.

jg